• Journal of Digital Convergence
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• v.14 no.7
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• pp.309-319
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• 2016

There is a need to develop a data quality management algorithm in order to improve the quality of health care data. In this study, we developed a data quality control algorithms associated diseases related to diabetes in patients with hypertension. To make a data quality algorithm, we extracted hypertension patients from 2011 and 2012 discharge damage survey data. As the result of developing Data quality management algorithm, significant factors in hypertension patients with diabetes are gender, age, Glomerular disorders in diabetes mellitus, Diabetic retinopathy, Diabetic polyneuropathy, Closed [percutaneous] [needle] biopsy of kidney. Depending on the decision tree results, we defined Outlier which was probability values associated with a patient having diabetes corporal with hypertension or more than 80%, or not more than 20%, and found six groups with extreme values for diabetes accompanying hypertension patients. Thus there is a need to check the actual data contained in the Outlier(extreme value) groups to improve the quality of the data.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.4
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• pp.137-146
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• 1999

Inspection becomes to be important in the safety of structure and economical viewpoint, because structural damage accompanies lots of economical cost and social problems. Especially ship structure is composed of a lot of members and it is impossible to inspect all members continuously. The purpose of this paper is to get optimal inspection plan containing inspection time and method. Crack is one of major modes on the structural failure and can lead to collapse of structure. In this paper, the deteriorating process, which contains inspection to detect the crack before the propagation to large crack, is idealized as Markov chain model. Genetic algorithm is also used to accomplish the optimization of inspection plan. Especially, the probabilistic characteristics of cracks are changed, because ship is operating in corrosive environments and the scantling of structural members is reduced due to corrosion. Non-stationary Markov chain model is used to represent the process of corrosion in structural members. In this paper, the characteristics of indivisual inspection plan are compared by numerical examples for the change of corrosion rate, the cost due to scheduled system down and target failure probability. From the numerical example, it can be seen that the improvement of fatigue life for the members with short fatigue life is the most effective way in order to reduce total maintenance cost.

• Journal of the Korean Society for Railway
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• v.19 no.2
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• pp.195-203
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• 2016

Concrete slab track was applied to the Gyeoungbu High Speed Railroad step 2 and the Honam High Speed Railroad. Concrete slab track incurs higher construction cost and lower maintenance cost than existing gravel track. For these reasons, the use of concrete slab track has increased in Korea. The biggest problem in the use of concrete slab track is repairing damage from settlement that can occur while trains are in service. High speed railroad design standards require allowable residual settlement of concrete slab track of less than 25mm. In order to satisfy the requirement of long term stability of concrete slab track, it is necessary to manage the secondary compression settlement within the allowable residual settlement. This study is to evaluate the secondary compression settlement with the variation of the secondary compression index, thickness of soft ground, and concrete slab track life. Statistical analysis is performed to determine the probability of distribution of areas where serious problems will be caused after the concrete slab track is constructed.

• Radiation Oncology Journal
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• v.4 no.2
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• pp.99-105
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• 1986

Optimal balance between control probability and risk of complication is emphasized even in present time, Although certain incidence of intestinal injury is accepted as an inevitable consequence after abdominopelvic irradiation, these complications still remain as problems. 60 mice were irradiated with 250 kVp orthovoltage x-ray machine and $200rad{\times}5/wk$ regimen. Histpathologic findings of colorectum and the relationship with occult blood test were analyzed and possible tolerable dose which would be safe from permanent complication was also estimated. Followings are the results: Mild mucosal and submucosal edema were observed in 1,000 rad irradiated group. Congestion of small vessels was prominent in 2,000 rad irradiated group and infiltration of inflammatory cells was observed in 3,000 rad irradiated group. Denuded mucosa was observed in 3,000 rad irradiated group. Occult blood test is not a proper indicator for rectal denuding or rectal ulcer, but our results suggest the possibility of using this as a relative scale of intestinal damage. Mitotic figures of crypt cells were observed even in 5,000 rad irradiated group, these suggest that the repair capacity of crypt cells are still functioning.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1916-1932
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• 2008

The railway accident is characterized by widespread and great(immerse) damage to our society when an accident occurred even if the probability of a railway accident is low. It is no doubt that the role of a rolling stock driver who are active in the first line of the rail safety driving is the most important to prevent an unexpected railway accident. Before new railway safety law being taken into effect, each railway operating organization had the responsibility of training a rolling stock driver by qualification criteria (the requirements or standards of competency), training period, probation period decided on their own standards. To train drivers driving same locomotive model, each railway operating organization had a variety of standards to draft and train trainees. Consequently, It was considered inefficient way to train and manage rolling stock drivers. However, after implementing the new railway safety law, a new system including training and evaluation process to issue driver's license on the condition that entire requirements are satisfied has been established. To prove the competency of the rolling stock driver objectively, training center and third-party evaluation center are divided individually and assigned by government office. Training center should design the training program to allot theatrical education time for different trainee group and to secure maximum practical training time utilizing simulator system to enhance the rolling stock driver's competency. This study analyzes certain conditions necessary to maximize the effectiveness and practical use of training for aquisition of a driver's license and the problems of the existing rail safety law and the ways to improve them.

• Korean Journal of Remote Sensing
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• v.35 no.2
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• pp.299-316
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• 2019

The purpose of this study was to analyze landslide susceptibility in the Pyeongchang area using Weight of Evidence (WOE) and Evidential Belief Function (EBF) as probability models and Artificial Neural Networks (ANN) as a machine learning model in a geographic information system (GIS). This study examined the widespread shallow landslides triggered by heavy rainfall during Typhoon Ewiniar in 2006, which caused serious property damage and significant loss of life. For the landslide susceptibility mapping, 3,955 landslide occurrences were detected using aerial photographs, and environmental spatial data such as terrain, geology, soil, forest, and land use were collected and constructed in a spatial database. Seventeen factors that could affect landsliding were extracted from the spatial database. All landslides were randomly separated into two datasets, a training set (50%) and validation set (50%), to establish and validate the EBF, WOE, and ANN models. According to the validation results of the area under the curve (AUC) method, the accuracy was 74.73%, 75.03%, and 70.87% for WOE, EBF, and ANN, respectively. The EBF model had the highest accuracy. However, all models had predictive accuracy exceeding 70%, the level that is effective for landslide susceptibility mapping. These models can be applied to predict landslide susceptibility in an area where landslides have not occurred previously based on the relationships between landslide and environmental factors. This susceptibility map can help reduce landslide risk, provide guidance for policy and land use development, and save time and expense for landslide hazard prevention. In the future, more generalized models should be developed by applying landslide susceptibility mapping in various areas.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.1
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• pp.19-26
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• 2003

Recently, the number of internet service companies is increasing and so is the number of malicious attackers. Damage such as distrust about credit and instability of the service by these attacks may influence us fatally as it makes companies image failing down. One of the frequent and fatal attacks is DoS(Denial-of-Service). Because the attacker performs IP spoofing for hiding his location in DoS attack it is hard to get an exact location of the attacker from source IP address only. and even if the system recovers from the attack successfully, if attack origin has not been identified, we have to consider the possibility that there may be another attack again in near future by the same attacker. This study suggests to find the attack origin through MAC address marking of the attack origin. It is based on an IP trace algorithm, called Marking Algorithm. It modifies the Martins Algorithm so that we can convey the MAC address of the intervening routers, and as a result it can trace the exact IP address of the original attacker. To improve the detection time, our algorithm also contains a technique to improve the packet arrival rate. By adjusting marking probability according to the distance from the packet origin we were able to decrease the number of needed packets to traceback the IP address.

• Journal of Platform Technology
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• v.8 no.3
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• pp.10-21
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• 2020

Partial discharge occurs a lot in high-voltage power equipment such as switchgear, transformers, and switch gears. Partial discharge shortens the life of the insulator and causes insulation breakdown, resulting in large-scale damage such as a power outage. There are several types of partial discharge that occur inside the product and the surface. In this paper, we design a predictive model that can predict the pattern and probability of occurrence of partial discharge. In order to analyze the designed model, learning data for each type of partial discharge was collected through the UHF sensor by using a simulator that generates partial discharge. The predictive model designed in this paper was designed based on CNN during deep learning, and the model was verified through learning. To learn about the designed model, 5000 training data were created, and the form of training data was used as input data for the model by pre-processing the 3D raw data input from the UHF sensor as 2D data. As a result of the experiment, it was found that the accuracy of the model designed through learning has an accuracy of 0.9972. It was found that the accuracy of the proposed model was higher in the case of learning by making the data into a two-dimensional image and learning it in the form of a grayscale image.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.6
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• pp.129-137
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• 2020

In performing the structural analysis, the foundation is considered to be a fixed end as a plastic hinge model. In this study, the displacements of the foundation, pier, and shoe were compared when the foundation modeled as a fixed end, a shallow foundation constructed on bedrock of 2m depth, and a pile foundation constructed in the 10m to 20m depth of bedrock. The shear force was also compared, and the probability of damage was calculated and compared for the critical condition. When calculated as a fixed end, the displacement of the foundation converged to 0mm, but the shallow foundation built on the bedrock with a depth of 2m caused relatively displacement, and the pile foundation constructed to contact the bedrock with a depth of 18m caused a larger displacement. In addition, it was analyzed that the displacement of the foundation, which is the lower structure, affects the displacement of the super structure, but the difference in shear force applied to the foundation was insignificant in the three cases. There was no difference between the shallow foundation and the pile foundation in the influence on the displacement of the top of the pier, but there was a big difference from the analysis assuming as a fixed end.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.3
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• pp.439-448
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• 2022

Recently, domestic small and medium-sized subcontractors participating in the overseas construction market are suffering from the continuous loss and damage due to the insufficient recognition of the importance of risk Sub-Clauses among conditions of subcontracts. Therefore, the need to derive risk Sub-Clauses for conditions of the subcontract has been raised, but until now, previous studies have been conducted focusing on deriving risk Sub-Clauses for standard conditions of contract for construction between the Employer and the Contractor. In this study, 52 risk Sub-Clauses were derived on the basis of the influence size of the Sub-Clauses through the Delphi technique targeting 94 Sub-Clauses of conditions of standard subcontract for construction edition 2011, issued by the International Federation of Consulting Engineers (FIDIC) and In addition, 33 key risk Sub-Clauses were finally derived through the PI Risk Matrix by Probability and Impact. The results of this study provide will useful information on key risk Sub-Clauses that need to be reviewed in advance to minimize contractual risks at the stage of bidding and signing contracts for overseas subcontract construction projects.